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HomeRepair HelpMars Central A/C RepairMars Central air conditioner is noisy or loud Repair
Mars Central air conditioner is noisy or loud
When a Mars central air conditioner is making a loud noise, rattling, buzzing, or the condenser fan is making noise, start by shutting off power at the disconnect box and checking for debris inside the outdoor condensing unit. Debris hitting the condenser fan blade is the most likely cause. Next, inspect the condenser fan motor. Worn bearings can cause AC fan motor noise, and the motor should turn smoothly by hand when power is off. Loose grille or cabinet panels can also vibrate and create air conditioner loud noise, so tighten any loose hardware. If the noise continues, inspect the condenser fan blade for damage, a loose set screw, or a loose motor shaft. A failing condenser fan motor may produce similar symptoms. Finally, a defective contactor can buzz and may prevent the condensing unit from cooling correctly. Because the contactor and fan motor involve 240V line voltage, avoid live electrical testing unless you are qualified; have a licensed HVAC technician handle those checks. Enter your Mars central air conditioner model number to find the exact replacement fan motor, fan blade, or contactor for your unit.
01 - Debris Hitting Fan
Over time debris can fall into the condensing unit, causing a noise when the fan is running. Inspect the fan blade and inside the unit for any debris. Clean out the outdoor unit as needed but be sure to shut off power to the unit before attempting to clean it out.
Top Solution
02 - Mars Central Air Conditioner Fan Motor
The fan motor has bearings that can wear out over time. When the bearings are worn out, they make loud noise. To check the bearings, try rotating the fan motor by hand. If the motor does not turn smoothly, replace it.
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Highly Likely
03 - Panels Vibrating
If the outdoor condensing unit is noisy, the grille or one of the panels may be loose and vibrating. Check for loose panels and tighten them as needed.
Highly Likely
04 - Mars Central Air Conditioner Fan Blade
The fan blade on the condenser fan motor might be defective or loose. To check the fan blade, wiggle the fan motor shaft. If the motor shaft is loose, tighten or replace the set screw. If the condenser fan motor is still making noise, replace the fan blade.
Less Common
05 - Mars Central Air Conditioner Condenser Fan Motor
The condenser fan motor has bearings that can wear out over time. When the bearings are worn out, they make loud noise. To check the bearings, try rotating the condenser fan motor by hand. If the motor does not turn smoothly, replace it.
Less Common
06 - Mars Central Air Conditioner Contactor
The furnace control board sends a low voltage signal to the contactor. When the contactor receives the signal from the control board, it closes the circuit, sending voltage to the condensing unit components. If the contactor is defective, it will not provide voltage to the condensing unit. In addition, the contactor will make noise when it is defective. If the condensing unit is making noise but not cooling, the contactor has probably failed. To determine if the contactor is at fault, use a multimeter to test the contactor for continuity. If the contactor does not have continuity, replace it.
Less Common
Frequently Asked Questions
Why is my Mars central air conditioner making a loud or rattling noise?
What should I check when the condenser fan is making noise?
Why is my AC making a buzzing noise and not cooling?
Can a noisy condenser fan motor cause my central air conditioner to stop cooling?
How do I find the correct Mars central air conditioner fan motor or fan blade?
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